scholarly journals THE USE OF HUMIC ACIDS FOR MODIFICATION OF BIODEGRADABLE FILMS MANUFACTURED ON THE BASIS OF POLYVINYL ALCOHOL AND HYDROXYPROPYLMETHYL CELLULOSE

2021 ◽  
Vol 6 ◽  
pp. 22-37
Author(s):  
Zhang Siaobin ◽  
V.V Lebedev ◽  
D.V Miroshnichenko
Keyword(s):  
Polyvinyl Alcohol ◽  
Mathematical Models ◽  
Humic Substances ◽  
Structure Formation ◽  
Humic Acids ◽  
Polymer Films ◽  
Biodegradable Polymer ◽  
Hydroxypropyl Methylcellulose ◽  
Specific Effect ◽  
Low Grade

The article is devoted to the problem of obtaining packaging materials that combine a high level of gas and / or moisture resistance and strength with the ability to quickly decompose without harmful effects on the environment. The purpose of the research described in the article is to study the possibility of making such a material, which, during the period of use, will not only be resistant to the effects of various bacteria, but even prevent their appearance, and upon burial it will be biodegradable. The initial components, namely polyvinyl alcohol, hydroxypropyl methylcellulose, and humic acids of coal origin (as antibacterial additives) were reasonably selected. The modifying effect of humic substances obtained from three different samples of low-grade Ukrainian coal has been studied. In the course of the studies performed, it was found that humic acids of different origins and with different characteristics have a specific effect on the processes of structure formation in solutions of polyvinyl alcohol and hydroxypropyl methylcellulose. In particular, it was shown that in polyvinyl alcohol and methylcellulose solutions with the addition of humic acids that do not contain particles of carbon residues of various degrees of dispersion, an increase in the formation of an ordered structure is observed. Micrographs of solutions of polyvinyl alcohol and hydroxypropyl methylcellulose with humic acids are presented. The peculiarities of the influence of humic substances on the processes of structure formation of solutions of polyvinyl alcohol and hydroxypropyl methylcellulose have been investigated in order to obtain hybrid environmentally friendly biodegradable polymer films. The corresponding experimental-statistical mathematical models have been developed, they describe the dependence of the conditional viscosity and conductivity of polyvinyl alcohol and hydroxypropyl methylcellulose on the content of humic acids, the duration of preparation and one of the characteristics of the raw materials used to obtain humic acids. The corresponding equations are given. Keywords: biodegradable polymer films, coal, humic acids, polyvinyl alcohol, hydroxypropyl methylcellulose, experimental statistical mathematical models Corresponding author Zhang Siaobin, e-mail: [email protected]

scholarly journals TECHNOLOGY FOR PRODUCING HUMIC SUBSTANCES FROM PEAT

2020 ◽  
pp. 55-60
Author(s):  
Zhanna Petrova ◽  
Vadym Paziuk ◽  
Anton Petrov
Keyword(s):  
Humic Substances ◽  
Humic Acids ◽  
Alkaline Solution ◽  
Chemical Activation ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Natural State ◽  
Low Grade ◽  
Extraction Temperature ◽  
Humus Layer

Humic acids are the most important component of soil humus. The higher their content, then the soil is fertile. However, in the natural state, humic acids are insoluble in water and little available to plants. They become available only after indirect action - humus mineralization, when it transforms into simple mineral compounds. In nature, more humic acids are found in low-calorie fuels - brown coal, peat and others. For power engineering, humic acids are an undesirable component, fuel with their high content is of low grade. However, for the production of humates - the more of them in the raw material, the better. Chemical activation of peat by treatment with an alkaline solution activates humic acids, which transform into a plastic water-soluble state. Humic substances of peat are both a natural astringent and a fertilizer useful for restoring the humus layer. The classical technology for the extraction of humic substances using chemical methods is based on high temperatures of the mixture and requires a lot of electricity. The proposed mode of extraction of the humus component according to the developed standard procedure takes place at an extraction temperature of 20 ° C, 60 ° C and the duration of treatment with an alkaline solution in a cavitation apparatus for 20 min, 40 min and 60 min. The research was carried out on milled and dry peat. The humic components in the humic substances were determined using a method adapted to our conditions. For the first time, the stage of extraction of humic components of peat, integrated into peat-processing production, made it possible to remove a sufficient amount of humic substances for the production of organic fertilizers. The remainder of the peat after extraction contains a sufficient amount of activated humic substances, which are a binding component for the production of peat briquettes.

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

scholarly journals Formulation and Optimization of Sodium Alginate Polymer Film as a Buccal Mucoadhesive Drug Delivery System Containing Cetirizine Dihydrochloride

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 619
Author(s):  
Krisztián Pamlényi ◽  
Katalin Kristó ◽  
Orsolya Jójárt-Laczkovich ◽  
Géza Regdon
Keyword(s):  
Drug Delivery ◽  
Tensile Strength ◽  
Sodium Alginate ◽  
Drug Delivery System ◽  
Delivery System ◽  
Polymer Films ◽  
Hydroxypropyl Methylcellulose ◽  
Chemical Properties ◽  
Active Pharmaceutical Ingredient ◽  
Swallowing Problems

Currently, pharmaceutical companies are working on innovative methods, processes and products. Oral mucoadhesive systems, such as tablets, gels, and polymer films, are among these possible products. Oral mucoadhesive systems possess many advantages, including the possibility to be applied in swallowing problems. The present study focused on formulating buccal mucoadhesive polymer films and investigating the physical and physical–chemical properties of films. Sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC) were used as film-forming agents, glycerol (GLY) was added as a plasticizer, and cetirizine dihydrochloride (CTZ) was used as an active pharmaceutical ingredient (API). The polymer films were prepared at room temperature with the solvent casting method by mixed two-level and three-level factorial designs. The thickness, tensile strength (hardness), mucoadhesivity, surface free energy (SFE), FTIR, and Raman spectra, as well as the dissolution of the prepared films, were investigated. The investigations showed that GLY can reduce the mucoadhesivity of films, and CTZ can increase the tensile strength of films. The distribution of CTZ proved to be homogeneous in the films. The API could dissolve completely from all the films. We can conclude that polymer films with 1% and 3% GLY concentrations are appropriate to be formulated for application on the buccal mucosa as a drug delivery system.

Preparation and physical characterization of cobalt iron oxide magnetic nanoparticles loaded polyvinyl alcohol

2021 ◽  
pp. 089270572098557
Author(s):  
M Abu-Abdeen ◽  
O Saber ◽  
E Mousa
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Saturation Magnetization ◽  
Polymer Films ◽  
Magnetic Hysteresis ◽  
Thermal Method ◽  
Cobalt Iron Oxide ◽  
Cobalt Iron ◽  
Iron Oxide Magnetic Nanoparticles

A solvent thermal method which depends on a thermal process under critical temperature and pressure was used to prepare cobalt iron oxide magnetic nanoparticles with a molar ratio 2. The prepared particles were in the form of nanoparticles with diameter ranging from 5 to 10 nm and with amorphous structure. Magnetic hysteresis behavior with saturation magnetization 36.31 emu/g and coercivity 4 Oe were observed for the nanoparticles. Polyvinyl alcohol was loaded with different concentrations of cobalt iron oxide nanoparticles using casting technique. Hysteresis loops for the polymer films were observed and both the saturation magnetization and coercivity were increased from 0.36 to 16.03 emu/g and 115 to 293 Oe for samples containing 5 and 20 wt% of nanoparticles, respectively. The elastic modulus of films was increased from 2.7 to 4.9 GPa for unloaded and loaded samples with 20 wt%, respectively. The storage modulus of the polymer films was found to obey the percolation behavior.

scholarly journals Effect of different levels of humic acids on the nutrient content, plant growth, and soil properties under conditions of salinity

2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy
Keyword(s):  
Plant Growth ◽  
Humic Substances ◽  
Humic Acids ◽  
Foliar Application ◽  
N Uptake ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Nutrient Elements ◽  
A Minor

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.

Resonant infrared pulsed laser deposition of thin biodegradable polymer films

2002 ◽  
Vol 74 (1) ◽  
pp. 123-125 ◽  
Author(s):  
D.M. Bubb ◽  
B. Toftmann ◽  
R.F. Haglund, ◽  
J.S. Horwitz ◽  
M.R. Papantonakis ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Polymer Films ◽  
Biodegradable Polymer ◽  
Pulsed Laser ◽  
Laser Deposition

Neptunium Speciation in Humic Acid-rich Clay Water upon Interaction With Radioactive Waste Glass Samples

2002 ◽  
Vol 757 ◽  
Author(s):  
V. Pirlet ◽  
P. Van Iseghem
Keyword(s):  
Humic Substances ◽  
Humic Acids ◽  
Specific Interaction ◽  
Waste Glass ◽  
High Level Waste ◽  
Boom Clay ◽  
Dissolution Tests ◽  
Vis Spectroscopy ◽  
Doped Glasses ◽  
High Level

ABSTRACTOrganic complexes of actinides are known to occur upon interaction of high level waste glass and Boom Clay which is a potential host rock formation for disposal of high level waste in Belgium. The solubility and mobility of 237Np, one of the most critical radionuclides, can be affected by the high dissolved organic carbon content of the Boom Clay porewater through complexation with the humic substances. The influence of humic substances on the Np behaviour is considered through dissolution tests of Np-doped glasses in Boom Clay water and through fundamental study of the specific interaction between Np(IV) and the humic acids using spectroscopic techniques. High Np(IV) concentrations are found in the glass dissolution tests. These concentrations are higher than what we should expect from the solubility of Np(OH)4, the solubility limiting solid phase predicted under the reducing conditions and pH prevailing in Boom Clay. Studying the specific interaction of Np(IV) with humic acids in Boom Clay porewater, high soluble Np concentrations are also measured and two main tetravalent Np-humate species are observed by UV-Vis spectroscopy. The two species are interpreted in terms of mixed hydroxo-humate complexes, Np(OH)xHA with x = 3 or 4. These species are the most likely species that can form according to the pH working conditions. Using thermodynamic simplified approaches, high complexation constants, i.e. log β131 and log β141 respectively equal to 46 and 51.6, are calculated for these species under the Boom Clay conditions.Comparing the spectroscopic results of the dissolution tests with the study of the interaction of Np(IV) with humic substances, we can conclude that the complexation of Np(IV) with the humic acids may occur and increases the solubility of Np(OH)4 upon interaction of a Np-doped glass and the Boom Clay porewater.

RHEOLOGICAL PROPERTIES OF HUMIC SUBSTANCES OF PEAT AND BROWN COAL

2021 ◽  
pp. 169-174
Author(s):  
Ivan I. Lishtvan ◽  
Vera N. Aleinikova
Keyword(s):  
Rheological Properties ◽  
Humic Substances ◽  
Structure Formation ◽  
Humic Substance ◽  
Brown Coal ◽  
Oil Wells ◽  
Alkaline Media ◽  
Rheological Parameters ◽  
Acid Media ◽  
Brown Coals

Knowledge about structure and rheological peculiarities of drilling solutions and reagents applied for the proceeding of oil wells has significant value for the forecasting of oil wells drilling. The research results of the structure of the humic substances of peat and brown coals precipitated in different pH ranges from the standpoint of their ability to structure formation on the base of the rheological curves obtaining of the flow of their dispersions and determining of their rheological parameters in terms of their application in drilling practice are given in the article. It is established that during transition from fraction, beset into alkaline media (12.0–8.5) to fraction beset into acid media (5.0–2.0) the decrease of the rheological indicators of caustobiolate humic substance is occurred. Rheological curves of the flow of the disperse of caustobiolate humic substances of the fraction 1 and 2 are characterized for strong fossil structures, disperses of humic substances of the fraction 3 is for less strong coagulation structures. Less structured are humic substances of brown coal so that their use is preferable for the regulation of the structure and rheological peculiarities of drilling solutions.

Application of self-healing, swellable and biodegradable polymers for wound treatment

2021 ◽  
Vol 30 (Sup9a) ◽  
pp. IVi-IVx
Author(s):  
Chukwuma O Agubata ◽  
Mary A Mbah ◽  
Paul A Akpa ◽  
Godwin Ugwu
Keyword(s):  
Wound Healing ◽  
Polyvinyl Alcohol ◽  
Biodegradable Polymers ◽  
Hydroxypropyl Methylcellulose ◽  
Composite Films ◽  
Self Healing ◽  
Moisture Uptake ◽  
Folding Endurance

Aim: Self-healing, swellable and biodegradable polymers are vital materials that may facilitate the different stages of wound healing. The aim of this research was to prepare wound healing films using self-healing polyvinyl alcohol (PVA), swellable hydroxypropyl methylcellulose (HPMC), biodegradable polyglycolic acid (PGA) sutures and ciprofloxacin antibiotic for improved treatment outcome. Methods: Films were formulated through aqueous-based mixing of varying amounts of polyvinyl alcohol (10–20% weight/weight (w/w)) and hydroxypropyl methylcellulose (0.5, 1% w/w) with fixed quantities of ciprofloxacin. PGA sutures were placed as grids within the wet mixtures of the polymers and ciprofloxacin, and thereafter products were air dried. The formulated films were evaluated for swelling ratio, breaking elongation, folding endurance, moisture uptake and loss, compatibility and in vitro antibiotic release. Furthermore, in vivo wound healing was studied using excision model and histopathological examinations. Results: Swelling ratios were above 1.0 and the films were minimally stretchable, with folding endurance greater than 500. Films were stable while moisture uptake and loss were observed to be less than 30%. Among the optimised hydrogel batches, those containing 10% w/w PVA and 1% w/w HPMC with no PGA showed the highest drug release of 73%, whereas the batches with higher PGA content showed higher percentage wound size reduction with minimal scar. The completeness of wound healing with batches containing PVA, HPMC, ciprofloxacin and PGA, along with the standard, is evident considering the massive cornification, regeneration of the epithelial front and stratum spinosum. Conclusion: The findings show that polymer-based multifunctional composite films are suitable for use as dressings for improved wound healing.

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